This is an interesting overview but it explains more the process followed by the author when a worked example might be more helpful to others.

If you found the author's post interesting and would like to see some practical examples of how to test for application security vulnerabilities, then the following will help get you up to speed:

http://www.owasp.org/index.php/Category:OWASP_Testing_Projec...

http://www.owasp.org/index.php/Category:OWASP_Code_Review_Pr...